Hydraulic accumulator



Patented May 22, 1934 UNITED STATES HYDRAULIC ACCUMULATQR Lewis Mervyn Cecil Seamark, Chagford, England Application November 2'7, 1931, Serial No. 577,576 In Great Britain February '7, 1931 10 Claims. (01. 103-222) t This invention relates to hydraulic accumulaors.

The invention has among its objects to provide an accumulator of simple construction that is especially adapted to provide a fluid medium under pressure for oil well equipment such as for the application of pressure in a blow-out preventer such as that described in the specification filed pursuant to a co-pending application, Serial No. 483,290 dated 20th September, 1930, patented January 2, 1934, 1,942,366, and generally to provide an accumulator of simple construc tion or for use in diflicultly accessible situations or where the erection of a plant under condi-' tions of more or less permanent instalment is diflicult, inconvenient or inessential. By a blowout preventer is meant an equipment mounted on the casing head of bore holes or wells and adapted for the purpose of passing into and withdrawing from the bore hole the casing or tools of varying size and form used in sinking the bore hole or well and permitting the tools used to be rotated without escape of oil or gas, whereby the boring may be continued before and after high pressures have been encountered and without loss at the surface of oil or gas under the pressure prevailing.

According to the invention an accumulator is provided the cylinder of which is formed as a tube that may be solid drawn and is mounted between end supports connected together by parallel bolts in such manner that fluid joints may be maintained between the ends of the tube and the end supports and in which the cylinder is supported horizontaly on parallel skids or upon a frame by which the aocmulator may thus be supported immediately above the ground without necessity of anchoring down upon a prepared foundation.

According to the invention moreover such an accumulator may be loaded by weights adapted to hang within pits provided adjacent the position at which the accumulator is set, the weights being suspended from the ends of a pair of ropes, cables or chains over a pair of pulleys carried at one end of the accumulator, the ropes, cables or chains being passed forward around pairs of pulleys in alignment that are carried upon the outer end of the accumulator ram, the ends of the ropes, cables or chains being advantageously anchored to the accumulator beneath the adjacent end support thereof.

According to the invention moreover such an accumulator is adapted to be loaded by fluid 55 pressure within a loading cylinder mounted in PATENT OFFICE alignment with the accumulator and whose ram is adapted to be connected to the outer end of the accumulator ram, as for example by the oppositely disposed ends of the rams being carried within or being connected to a crosshead 0 mounted .to slide in a position between the accumulator and the loading cylinder whereby pressure from the well or from some other convenient source is adapted to be used for loading the accumulator instead of or in addition to its being loaded by weights.

The invention comprises the features which are hereinafter described.

The invention is illustrated by way of example in the accompanying drawing in which Figure 1 represents in elevation partly in section an accumulator constructed and operating according to the invention.

Figure 2 is an elevation corresponding to Figure 1.

In carrying the invention into efiect according to the construction illustrated in the accompanying drawing, I provide two cylinders 11, b in alignment with connected rams c, d, the cylinder 0!. being the accumulator cylinder, and the cylinder b being for loading the accumulator with the well pressure, intercepted for example in a closed pressure vessel or with any other fluid pressure medium available from some other source, that may be used in addition to or instead of loading by the use of weights. The respective cylinders a, b may be made of solid drawn tubing, while the rams c, d may also be made as tubes closed at the ends, or they may be made solid and of stainless steel. The cylinder a and ram 0 of the accumulator may be respectively smaller in diameter than the loading cylinder b and ram d. Thus for example the accumulator cylinder a and ram 0 may be respectively 4 inches and 2 inches in diameter, and the loading cylinder b and ram d may be respectively 4 inches in diameter and 3 inches in diameter. It will however be understood that no limitation is involved to particular dimensions, those indicated being merely exemplary, and the respective parts may bev designed and dimensioned according to particular practical requirements.

The respective cylinders a, b are mounted in alignment so as to be set in a horizontal position near the ground level, for which purpose end supports e, f, g, h are provided between which the respective cylinders or tubes are set.

The end supports e, f of the accumulator cylinder and the end supports 9, h of the loading cylinder are connected together to engage the respective cylinders between them by four or other number of bolts 1', :i conveniently set at equal distances apart, and the inner faces of the end supports are advantageously provided with an annular groove is for the reception of packing. The respective ends of the cylinders are set within the respective annular grooves whereby on nuts being applied upon the screw-threaded ends of the bolts 2', 7', eiTective fluid tight joints are maintained between the respective end fittings and the respective cylinders.

Vertical pillars or bars Z, m are provided at each side of the end supports and are connected respectively to parallel longitudinal members n of channel iron section adapted to serve as skids extending beneath the respective cylinders and beneath the space provided between them across which the rains extend. The lower flanges n of the respective skids at the ends may be inclined upwardly to adapt the longitudinal members to serve as skids in the haulage of theapparatus into or out or" its position of use.

It will be understood that the cylinders are advantageously supported immediately above the 1 ground, the centres of the rams c, (1 being for example disposed a little more than one foot or more above the ground or supporting surface of the apparatus.

The endsupports e, f, g, h at the inner and I outer ends of the respective cylinders may be made substantially rectangular in cross-section to yield flat lateral faces at each side against which the vertical pillars or bars Z, m may be secured, the lower ends of which may be secured a at the flat inner faces of the respective skids 71..

To the outer end support e of the accumulator cylinder at e a pipe connection may be made to the apparatus to which the. fluid pressure medium has to be supplied such as the blow-out preventer of a casing head equipment for a bo-re-.

hole or well, while at the outer end support h of the loading cylinder at h a pipe connection is made to a pressure container to which the well is accessible, or to a pump or to any other convenient source of a fluid pressure medium.

The inner end supports .1, y of the respective cylinders are arranged for the reception of hydraulic packing and gland rings 9 ,1 through which the respective rams c, d may pass.

The distance apart of the inner pillars or bars Z, m of the accumulator and loading cylinders a, b is determined according to the stroke of the rams c, d. The respective cylinders and rams are arranged in alignment, and the adjacent outer ends of the respective rams are connected to the same crosshead 0 which is supported or guided by suitable means such as hereinafter described. The crosshead o is also adapted for the reception of a horizontally disposed spindle 0 or of trunnion pins at each side, upon the outer ends of which pulleys p may -be respectively mounted to receive ropes or other flexible elements q, one end of each rope being anchored in position at q beneath the inner end support 1 of the accumulator cylinder. The two ropes q pass rearwardly above the accumulator to the outer end, where a pair of pulleys p are mounted in brackets p carried by the end support 6 and in alignment with those carried by the movable crosshead o, the pair of pulleys :0 being disposed in position so that the ends of the ropes q may depend for the support of weights set within an adjacent pit. Instead of weights as commonly used in accumulators a casing q may be provided filled with any conveniently accessible ballast, the casing q being made of a determined capacity so that the pressure to be applied upon the accumulator ram 0 may, if required, be produced by weight alone and by filling in the casing with ballast of any convenient kind.

The inner end supports g of the accumulator and loading cylinder are connected together by rods or bolts T which conveniently may be provided in pairs at equal distances above and below the ram centres, so that lines connecting the rod or bolt centres form a rectangular figure having opposite sides horizontally and vertically disposed. The rods or bolts r are provided at the ends for connection to the inner end supports 1, g in such manner as to be permitted lengthwise adjustment. The pairs of rods or bolts 1' at each side mayserve for the support of lateral guides for the crosshead 0. These guides may for example be provided as parallel flat bars 8, one disposed above the other and may be spaced apart a distance corresponding to the diameter of the end of the spindle or of the trunnion pins 0 on which the pulleys are respectively mounted, so that thus the crosshead o and the ends of the rams carried by the crosshead may be supported in their movement. For this purpose the bars s are disposed in pairs at each'side, the bars of each pair being disposed one above the other and being supported at their respective ends by vertically disposed bars s suitably secured to the adjacent rods r, vertically disposed bent bars s being secured at the respective upper and lower ends of the vertically disposed bars 8 so that thus the respective rods 1- are engaged between the vertical bars 8 and the bent bars s in the manner illustrated in Figure 2. By such means a rigid guiding frame is provided which is mounted upon and supported by the rods 1' for guiding the spindle or trunnions o and supporting the crosshead 0 in its movement.

It will be understood that the loading cylinder b may alternatively be adapted for use as the accumulator cylinder by provision at q being made for the anchorage beneath its inner end support of the ends ofthe pair of ropes q and by mounting pulleys in alignment with those carried by the crosshead, upon the outer end support it of the cylinder, by the use of brackets such as p in a manner similar to that in which the pulleys p are mounted in the manner hereinbefore described, the opposite end of the ropes depending from a position beyond the outer end of the cylinder b and support 71, for suspending a weight or Weights in the manner hereinbefore described.

The respective ends of the ropes q may be connected to bolts (1 anchored to a transversely disposed member (P which may be carried beneath and secured to the lower pair of bolts 2' 01' 7' connecting the end supports of the cylinder serving asthat of the accumulator, this transversely disposed member q being advantageously provided of a channel section, and the bolts 11 being supported transversely through the respective webs thereof.

It will be understood that in the described arrangement of the ropes q by which the accumulator is loaded with weights, the extent of movement of the latter is equal to twice the stroke of the accumulator ram; and that the accumulator may be loaded by fluid pressure medium under pressure, or by weights, or by both these means.

I claim:

1. An accumulator comprising a horizontally disposed pressure cylinder, a horizontally disposed loading cylinder in alignment with the pressure cylinder, a free support common to the said cylinders disposed parallel with and immediately beneath the said cylinders in lengthwise lying position, means by which the said pressure and loading cylinders are connected to and car ried upon the said common and free support to render the said cylinders movable together from place to place, rams for the pressure cylinder and loading cylinder respectively and means for connecting the rams together and for their support in their movement out of their respective chambers.

2. An accumulator comprising a pressure cylinder, a loading cylinder in alignment with the pressure cylinder, rams for the pressure cylinder and loading cylinder respectively, means for connecting the rams together comprising a common crosshead adapted to move in position between the opposite ends of the pressure and loading cylinders, parallel lateral guides for the common crosshead, and parallel disposed rods for the connection together of the pressure and loading cylinders.

3. An accumulator comprising a pressure cylinder, a loading cylinder in alignment with the pressure cylinder, the pressure and loading cylinders being formed as tubes, end supports for the pressure and loading cylinders, parallel rods adapted to connect the respective sets of end supports together whereby fluid-tight joints are maintained between the ends of the respective cylinders and end supports, frame members disposed lengthwise beneath the cylinders and adapted for mounting thereon the end supports for carrying the said cylinders.

4. An accumulator comprising a pressure cylinder, a loading cylinder in alignment with the pressure cylinder, the pressure and loading cylinders being formed as tubes, end supports for the pressure and loading cylinders, parallel rods adapted to connect the respective sets of end supports together whereby fluid-tight joints are maintained between the ends of the respective cylinders and the end supports, and parallel members adapted to serve as skids upon which the said cylinders are supported by the connection therewith of the end supports.

5. An accumulator comprising a pressure cylinder, a loading cylinder in alignment with the pressure cylinder, the said cylinders being formed as tubes, end supports for the said cylinders, parallel rods adapted to connect the respective sets of end supports together whereby fluid-tight joints are maintained between the ends of the respective cylinders and the end supports, rams for the said cylinders, means for connecting the rams together comprising a common crosshead adapted to move in position between the oppositely disposed ends of the respective cylinders, parallel lateral guides for the common crosshead, parallel rods for connecting the said cylinders together, parallel members disposed lengthwise beneath the cylinders and adapted to serve as skids, and upright elements by which the said end supports are carried upon the skids.

6. An accumulator comprising a horizontally disposed pressure cylinder, a horizontally disposed loading cylinder in alignment with the pressure cylinder, rams for the pressure cylinder and loading cylinder respectively, means for connecting the rams, together and for their support in their movement out of their respective cylinders comprising a member adapted to carry a pair of pulleys, and means by which the said pressure cylinder is adapted to be loaded by weight comprising the said pair of pulleys, a corresponding pair of pulleys carried at the end of the said pressure cylinder and a pair of flexible elements passing round the respective pulleys of the said pairs disposed in alignment, one end of which flexible elements is held while from the other ends the said weight depends.

'7. An accumulator comprising a horizontally pressure cylinder, a horizontally disposed loading cylinder in alignment with the pressure cylinder, rams for the pressure and loading cylinders, means for connecting the rams together and horizontally disposed and free supporting members disposed lengthwise immediately beneath the cylinders and parallel with them and adapted to serve as ground skids upon which the said cylinders are supported in lengthwise lying position and adapted to be moved on the said skids.

8. An accumulator comprising a pressure cylinder, a loading cylinder in alignment with the pressure cylinder, rams for the pressure and loading cylinders, respectively, means for connecting the rams together, and means by which the loading cylinder is alternatively adapted for use as an accumulator.

9. A transportable accumulator adapted for haulage comprising a pressure cylinder formed as a tube, end supports for the cylinder, parallel rods adapted to connect the end supports together whereby fluid-tight joints are maintained between the ends of the cylinder and the end supports, parallel members disposed lengthwise beneath the cylinder and adapted as skids for mounting the end supports for carrying the cylinder, and transportable means for loading the accumulator, substantially as hereinbefore described.

10. A transportable accumulator adapted for haulage, comprising a horizontally disposed pressure cylinder formed as a tube, end supports for the cylinder, parallel disposed and horizontal rods adapted to connect the end supports together, whereby fluid-tight joints are maintained between the ends of the cylinder and the end supports, frame members disposed beneath the cylinder and adapted for mounting the end supports for carrying the cylinder, and means for loading the accumulator, substantially as hereinbefore described.

LEWIS MERVYN CECIL SEAMARK. 

